Metalliferous ore product.



A. S. DWIGHT ISL R, L. LLOYD.

METALLLPERDUS ORE PRODUCT.

APPLICATION FILED APR,9,1908

RENEWED DEO.8,1910.

Patented Mar. 12, 1912.

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METALLIFEROUS ORE PRODUCT.

,1908. RENEWED DEC. 8, 1910.

APPLICATION FILED APR, 9

Pa tented Mar 12, 1912.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

ARTHUR S DWIGHT AND RICHARD L. LLOYD, OF NEW YORK, N. Y., ASSIGNORS, BY .MESNE ASSIGNMENTS, TO DWIGHT & LLOYD METALLURGICAL COMPANY, f OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

METALL-IFEROUS ORE PRODUCT.

Application filed April- 9, 1908, Serial No. 426,101.

tion, reference being had therein to the accompanying drawing.

This inventionrelates to an improved metalliferous product adapted to be used in a. blast furnace or other kind of metallurgical furnace in deriving metal therefrom, obtained by sintering the material being treated. to produce the product, as for instance a finely divided ore or metalliferous material containing a combustible constituent; and the fines of sulfid ores, such as galena, pyrites, and analogous materials may be regarded as types of material from which, belng properly treated, the product constitut-- ing the subject of this case may be made.

The products obtained by following the various earlier desulfurizing and sintering processes are fully understood by metallurgists skilled in the art,and it is unnecessary to here describe, in detail, either these, or the modes of treating the ores by which such earlier products are obtained. Referring especially to materials initially containing sulfur it is suflicient for p esent purposes, to note that the desulfurize products known in the earlier art may be regarded as of one or the other of two sorts, mechanically considered, those of one sort being masses which, throughout, are in a finely divided condition although desulfurized), and the products 0 the other sort being masses each consisting partly of non-uniformly sintered blocks or cakes and partly of desulfurlzed fines. Those products which are above referred to as masses composedof desulfurized fines are commonly obtained by using a long roasting hearth For rabbling furnace wherein it. is impossible to roduce sintered blocks or cakes of the re'latlvely large sizes that are necessary. for good work in the blast furnace because of the fact that the agitating or rabbling treatment of the ore whileifin the floor or hearth of the furnace prevents the formation of such blocks or cakes. In such fur. naces the fire or heated currents of gas are Specification of Letters Patent.

Patented Mar. 12, 1912. Renewed December a, 1910. Serial 110,596,375.

generally above the ore mass and move across its upper surface, and consequently, it is requisite that the mass should be frequently stirred, agitated orrabbled, so as to exposethe masses or particles which are beneath the surface to the oxidizing action. The products of the other class, the second above referred to, may be here typified by that obtained, during late years, from what is known in the art as the Huntington- Heberlein process. In following this mode of treatment amass of fines, such as copper sulfid, is placed in a large vessel or receptacle, generallybowl-shaped and of such dimensions that it can hold a mass of ore fines several feet deep and several feet in hori zontal diameter. The product of this process in each instance is a mass of desulfurized ore comprising two sub-masses, one of which,

is a large block or cake, gradually increasing in hardness from the top to the bottom, and the other sub-mass being a body of loose pulverulent fines which although desulfurvized are not sintered, and frequently constituting as much as a third of the entire mass,

the bottom to the top. The different strata,

considered horizontally, are subjected to differing pressures varying with the distance from the top. The lowermost strata:-

are subjected to the greatest pressure and. have their particles pressed together more tightly. As the mass is several feet (frequently three to five) in depth, the weight of the metallic orewhich rests on the bottom 7 portion ofthe mass is considerable. But the weights upon, and the corresponding pressures exerted by, the strata, gradually decrease upward. The air as it rises through the mass becomes more and more eflicient as an agitating, disturbing, or lifting agent.-'

The weights and pressure above referred to serve to prevent the air, as it moves through the lower part of the mass, from agitating or disturbing the particles in that part, and

they are not prevented by it from sintering with each other. But, through the upper section (approximately the upper third of the mass) the air can move with such force as to agitate the particles, even forming blow-holes or craters, and with the result that the ore particles in this uppermost region can not sinter, a state of substantial quiescence and rest being necessary to effect the sintering. Consequently the sub-mass at the top of the charge, considered as an entirety, in the desulfurizing receptacle, is a body of pulverulent particles which, although desulfurized are still finely reduced and not in condition to be introduced into a blast furnace to advantage. The other sub-mass of the charge, the large sintered block at the bottom, must, after the desulfurizing stage, be broken up into small pieces or lumps preparatory to charging into the blast furnace. For this breaking much labor is required not only because of the large size of the sinter, but also because of the excessive hardness of its lower strata. The upper strata are more easily broken, and the porosity in that region is generally that which is desirable for the actions which are desired in the furnace; whereas the lower strata are much harder and more refractory, presenting greater difliculty in the breaking up, and the blocks or pieces obtained therefrom by such breaking are much less permeable to the reducing gases in a blast furnace.

In contrastv with the earlier products (characterized by the above disadvantages) derived from following the'commonly used processes of desulfurizat-ion and sintering, we have succeeded in furnishing for the blast furnace a desintered product of such nature that it is, throughout, uniformly the same in porosity, permeability, and hardness, along horizontal lines and along vertical lines, and can be produced in indefinitely large quantities, which are, throughout, uniform in the above respects.

While we have referred especially to materials initially containing sulfur and requiring desulfurization, it will nevertheless be understood that ourinvention is not thus limited and that our improved product may be formed ofany metal bearing or other material capable of being sintered.

We effect the sintering of the ore while it is arranged in relatively thin, uniformly distributed, masses or layers. And the important results are that there occurs com plete sintering of the entire mass of'fines in the stratum'or layer, air being conducted through it in such Waythat none of its particles are agitated or disturbed to an eX- tent to prevent complete and uniform sintering. The internal combustion resulting from the oxidizing of the sulfur or other combustible constituent insures a uniform sintering action from one surface of the mass to the other. By suitably holding the ore, and causing the air to travel through it in a suitable way, the retaining of the particles in the quiescent state can be secured even though the layer is thin and does not have any part of its. mass exert any considerable weight upon another-part; the sintering, here, not depending upon the action of gravity or upon the pressure of the upper part of the ore mass upon the lower part.

\Vhile the characteristics incident to our product are notnecessarily limited to a sinter of any precise dimensions or composition, wehave found that the material for the blast furnace is in the best condition when produced from a layer or stratum of fines which is from two to five inches in thickness. We prefer to manufacture this product in an apparatus which carries the stream or stratum of ore, more or less nearly continuously, from point to point, while the sintering action is occurring; and because of treating it while it is thus in motion, there is economy in time and labor which more than compensates for what would apparently be a loss due to the thinness of the. mass. To obtain our product in this way, use can be-made of any of several forms of mechanism. In order that the present invention, may be fully understood we have selected for illustration in the drawings herein one of the simpler forms of mechanism for this purpose, although it is to be understood that neither the mechanism nor the method of using it enters essentially into the present subject matter.

Figure 1 is a side view, partly in section, of an apparatus in which our improved metal bearing products can be made. Fig. 2 is a plan "view. Fig. 3 is a perspective View of a sample of the product, the right hand end illustrating the appearance of the interior when the sample is cut on a transverse plane.

Inasmuch as an apparatus of the kind generally indicated more or less conventionally in the drawings is described in our Patent No. 916,394 issued March 23, 1909, it is not necessary to describe it here in all of. its details. Sufiice it to say that T indicates an orecarrying and supporting elenient which is drum-like in construction, having flange walls t, with inward projecting ring-sections t and the ore-supporting part N, the latter being formed of perforated or barred sections clamped in place. The drum is supported by means of rings 0 which rest upon and, are actuated by rollers P and Q. 1

'- At G the sulfur ingredients or other combustible elements of the mass are ignited, there being at this transverse line a gas pipe from which the gas jets issue toward the top surface of the ore. The air suction apparatus being set in operation, air is drawn downward through the burning layer and the gases are taken into the box H andwithdrawn thence by the exhaust mechanism.

Inasmuch as the air moves downward through the ore, it has no lifting or disturbing action upon it. The particles at the upper surface of the stream remain in quiescence relatively to each other, and those at the lower surface are held against displacement by the holder (the perforated floor, the grate sections, or the like) and sintering is not interfered with. By the time the ore reaches the lilnitof the air box the sintering is completed and the sinter is ready for removal. As the relatively thinsolid mass reaches the take-off device at K, it is separated from the drum and slides down the chute, the action at this point in the apparatus automatically breaking the sinter mass into relatively small blocks or cakes which can be readily picked up by the operatives or loaded upon vehicles and transported to the blast furnace ready for charging therein. As the quiescence of .the particles extends from the 'topto the bottom of the mass the sintering is uniform through the entire layer, and as there is noconsiderable pressure experienced by one stratum of the ore from the weight of the superincumbent strata there results a practically uniformity in the porosity of the sinter not only along lines longitudinal of its mass but on transverse lines and on vertical lines. The lower stratum is no harder or more indurated than are the strata above it, for the stream being only a few inches in thickness there is no pressure-generating weight upon'the lower particles. By ref- 'tially made for instance,

erence to Fig. 3 some of thephysical characteristics of this desul-furized sinter will be found conventionally delineated. As the layer of material being sintered is inipractically smooth, that is, as smooth as results from -feeding the material to a moving support to form a layer of uniform thickness, and

contained in the sintered masses.

What we claim is:

asthe layer rests upon a smooth though perforated or apertured support,'the resulting sinter has a top surface and a bottom surface which are also correspondingly smooth and well defined, there being in these surfaces uniformly distributed and uniformly sized pores or gas passages. And as the layer is comparatively thin, the texture and consistency of the sinter in respect to its porosity and permeability are uniform from the top surface, through the body, to the bottom surface. This sintered product is not only of substantially uniform porosity but is self-sustaining and capable of maintaining its shape though subject to considerable weight or pressure, which in sures that when introduced into a smelting furnace the oxldizing, reducing, or other gases whichare forced through the furnace and the material contained therein readily pass through the body of each piece of the sintered product as well as through masses thereof which may be comprised in the layers or strata of the furnace charge, thus bringing the heat and the reducing or oxidizing gases into very close and intimate relation with the metal being treated ii ilild e blocks or pieces of sintered material produced according to our process herein described are, owing to their porosity, relatively light and of .relatively low specific gravity as compared with its own metallic and other constituents.

While we have referred to our improved product as normally having its oppositely disposed. surfaces relatively smooth and well defined, it will be understood that many of the advantageous features incident to our invent-ion are present in those smaller fragments of material which may result from the breaking up of initially complete and regularly formed cakes. In fact, in many cases the smaller bodies are found preferable for treatment in a smelting furnace. The partial breaking up or disintegration of the cakes in those cases where it is found to be desirable or unavoid able, is not to be construed as removing the product from within the scope of our in-, '115 vention. On the contrary, our invention is to be understood as relating broadly to uniformly porous sinter cakes or blocks initially having relatively smoothand well de-.

fined surfaces, and this irrespective of the treatment which the cakes may undergo subsequent to format-ion and after leaving the perforated grate sections upon which they are first supported.

1. The herein described metalliferous product adapted for use in obtainingmetals in a smelting furnace, the same being a block of sintered ore havingnormally smooth top and bottom surfaces and uni- [Correction in Letters Patent No. 1,020,345.

surface to the bottom surface and being I uniformly porous and permeable to gases at the said surfaces, and throughout the body between them, substantially as set forth.

3; The herein described met-alliferous product adapted for use in obtaining metal this correction therein that the Patent 0mm.

[seam] N. Y., for an improvement in Metalliferous Ore Products,

ina smelting furnace or equivalent, it being arelatively thin block or cake of desulfurized, sintered ore with relatively smooth upper and lower surfaces, and a body part between them, said surfaces and body being uniformly porous and permeable to gases, substantially as set forth.

In testimony whereof we afiixour signatures in presence of two witnesses.

ARTHUR S. DWIGHT. RICHARD L. LLOYD. Witnesses:

H. J. STEBLI,

GRACE ELIZABETH SEYMOUR.

It is hereby certified in Letters Patent No. 1,020,345, granted March 12, 1912, upon the application of Arthur S. Dwight and Richard L. Lloyd, of New York,

an error appears in the printed specification requiring correction as follows: Page 2, line 36, for theword desintered read sintered; and that the said Letters Patent should be read with same may confor n to the record of the case in the Signed and'sealed this16th'day of April, A. 1)., 1912.,

o. o. BILLINGS, Act'zbzg Commissioner of Patents.

[Correction in Letters Patent No. 1,020,345.

surface to the bottom surface and being I uniformly porous and permeable to gases at the said surfaces, and throughout the body between them, substantially as set forth.

3; The herein described met-alliferous product adapted for use in obtaining metal this correction therein that the Patent 0mm.

[seam] N. Y., for an improvement in Metalliferous Ore Products,

ina smelting furnace or equivalent, it being arelatively thin block or cake of desulfurized, sintered ore with relatively smooth upper and lower surfaces, and a body part between them, said surfaces and body being uniformly porous and permeable to gases, substantially as set forth.

In testimony whereof we afiixour signatures in presence of two witnesses.

ARTHUR S. DWIGHT. RICHARD L. LLOYD. Witnesses:

H. J. STEBLI,

GRACE ELIZABETH SEYMOUR.

It is hereby certified in Letters Patent No. 1,020,345, granted March 12, 1912, upon the application of Arthur S. Dwight and Richard L. Lloyd, of New York,

an error appears in the printed specification requiring correction as follows: Page 2, line 36, for theword desintered read sintered; and that the said Letters Patent should be read with same may confor n to the record of the case in the Signed and'sealed this16th'day of April, A. 1)., 1912.,

o. o. BILLINGS, Act'zbzg Commissioner of Patents.

It is hereby certified that in Letters Patent No. 1,020,345, granted March 12, 1912, upon the application of Arthur S. Dwight and Richard L. Lloyd, of New York,

N. Y., for an improvement in Metalliferous Ore Products, an error appears in the printed specification requiring correction as follows: Page 2, line 36, for the word desintered read se'ntered, and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the casein the Patent Oflice.

Signed and sealed this 16th day of April, A. D., 1912.

C. C. BILLINGS,

Act mg Commissioner of Patents.

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